Mesoclimas de pastizales de la Sierra de la Ventana
Abstract
This study was conducted to recognize local differences in climate, between the main grassland types in the Sierra de la Ventana, Argentina. We compared 6 sites with different elevation, slope and aspect in a W-E attitudinal transect (400-1100 m asl). Simultaneous hourly data were registered during selected representative days of every season. The climatic variables measured were: air temperature, relative humidity, atmospheric saturation deficit pressure, light intensity, wind velocity, air evaporative capacity, and soil temperature. PCA was applied for seasonal and annual comparison of sites. We concluded that the sites showed sufficient climatic differences to recognize 6 mesoclimates. The greatest dissimilarity occurred between lowland and mountain sites. The former were warm, anisothermic and showed higher diurnal evaporative capacity. Steep SW slopes were similar to the lowland sites in summer, but in the other seasons were cold, isothermic, very humid and received low radiation; they seemed more continental. Mountain summits and high ridges showed extreme climatic conditions: they were colder, windy, and had the highest evaporative air capacity, reduced in winter because of the high cloudiness enclosing them. NE and SW gentle slopes showed intermediate conditions between the upper and lower sites; both sites showed differences that were clearly related to aspect. The temperature gradient observed support the existence of an altitudinal bioclimatic unit, a montane belt located above 750 m asl, unique in the province of Buenos Aires.
References
Burgos, J.J. 1969. El clima de la Provincia de Buenos Aires en relación con la vegetación natural y el suelo. En: Cabrera, A. L. (Eds.), Flora de la Provincia de Buenos Aires, Tomo I :33-99.
Burgos, J. J. y A. L. Vidal. 1951. Los climas de la República Argentina según la nueva clasificación de Thornthwaite. Meteoros 1:3-32.
Cabrera, A. L. 1971. Fitogeografía de la República Argentina. Bol. Soc. Arg. de Botánica, 14:1-42.
Cappanini, D. A., C. O. Scoppa y J. R. Vargas Gil. 1971. Suelos de las Sierras Australes de la Provincia de Buenos Aires. Págs. 203-334. En: Reunión sobre la Geología de las Sierras Australes Bonaereses, CIC, La Plata.
Ewel J. J. y J. L. Whitmore. 1973. The Ecological Life Zones of Puerto Rico and the U. S. Virgin Islands. Forest Service Research Paper ITF-18. Puerto Rico. 72 págs.
Geiger, R. 1971. The climate near the ground. Harvard University Press (3o ed.), USA. 611 págs.
Griffiths, J. F. 1968. Applied climatology. An introduction. Oxford University Presss. 118 págs.
Holdridge, L. 1947. Determination of world plant formations from simple climatic data. Science 105 (2727):367- 368.
Holdridge, L. 1978. Ecología basada en Zonas de Vida. Inst. Iteram. de Cs. Agr., San José, Costa Rica. 216 págs.
Kreeb, K. 1977. Methoden der Pflanzenokologie. Gustav Fischer Verlag, Stuttgart - New York. 235 págs.
Kristensen, M. J. 1992. Características Microclimáticas de las Sierras de Ventana y su relación con la Vegetación. Tesis Doctoral. Fac. de Cs Nat. y Museo, Univ. Nac. de La Plata. 380 págs.
Orloci, L. y N. C. Kenkel. 1985. Introduction to data analysis with examples from population and community ecology. International Co-operative Publishing House, USA. 240 págs.
S. M. N. 1981. Estadística Climatológica. 1961 - 1970. Servicio Meteorológico Nacional, Fuerza Aérea Argentina.
S. M. N. 1986. Estadística Climatológica. 1971 - 1980. Servicio Meteorológico Nacional, Fuerza Aérea Argentina.
Unwin, D. M. 1980. Microclimate measurement for ecologists. Academic Press, London. 97 págs.
William G. D. V. y J. Brochu. 1969. Vapour pressure deficit vs. relative humidity for expressing atmospheric moisture content. Naturaliste Canadien, 96 :621-636.
Downloads
Published
How to Cite
Issue
Section
License
Authors retain their rights as follows: 1) by granting the journal the right to its first publication, and 2) by registering the published article with a Creative Commons Attribution License (CC-BY 4.0), which allows authors and third parties to view and use it as long as they clearly mention its origin (citation or reference, including authorship and first publication in this journal). Authors can make other non-exclusive distribution agreements as long as they clearly indicate their origin and are encouraged to widely share and disseminate the published version of their work.